


Dimensional Misappropriation

by withasideofangst



Category: Harry Potter - J. K. Rowling
Genre: (not my first fanfic overall), Alternate Timelines, Alternate Universe - Canon Divergence, Dimension Travel, Don't copy to another site, Fucking Up The Timeline, Gen, Master of Death Harry Potter, My First Work in This Fandom, Not Canon Compliant - Movie 2: Fantastic Beasts: The Crimes of Grindelwald, One Shot, Powerful Harry, Professor Albus Dumbledore, Teenage Tom Riddle, Temporary Character Death, The Author Regrets Nothing, Time Travel, because no, but only of things he did in canon really, minor albus dumbledore bashing, somewhat ooc Grindelwald
Language: English
Status: Completed
Published: 2019-09-26
Updated: 2019-09-26
Packaged: 2020-10-30 18:37:30
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,496
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20777627
Author URL: https://archiveofourown.org/users/withasideofangst/pseuds/withasideofangst
Summary: (Also known as: how to fuck up a timeline)This is gratuitous nonsense and an excuse for me to write an older, bearded (and slightly tired of getting called on to do this sort of thing, thank-you-very-much) Harry Potter dueling an (also older) Gellert Grindelwald, as well as them both fucking up an entire alternate universe's timeline.Also features enemies casually delaying a fight in order to monologue to their audience, as one does when one has run out of fucks to give, and me having way too much fun writing in a new fandom.---“Unfortunately,” the man replied, “I’ve been told I have a bit of a--”“--saving-people thing,” they finished together.“Yes, I’ve heard,” Grindelwald continued.





	Dimensional Misappropriation

**Author's Note:**

> I would like to point out that I don’t really know how to write Grindelwald, considering I'm ignoring the Fantastic Beasts movies, and a lot of this is gratuitous nonsense and an excuse for me to write dueling and monologuing. But anyway, I decided Grindelwald could be a bit more...well-mannered about his fights than would be sensible. And also prone to monologuing, as one does when one is a dark lord, I suppose. Plus this version is more old-as-balls and is out of fucks to give. He’s just fucking with the world for fun at this point…
> 
> Also, Harry's appearance is based off of this: http://fav.me/darsgnn
> 
> Enjoy!
> 
> (And thanks to Sablesilverrain for catching some of my grammar mistakes.)

The false sky in Hogwarts’ great hall was dark and stormy.

This, while unusual, wasn’t truly a cause for alarm, and the enchantment never actually produced real rain or lightning without prompting from a professor, so while the phenomenon was strange in contrast to the clear skies outside, the students and staff were largely ignoring it.

They did not ignore, however, the hall doors slamming open shortly before the end of dinner.

The doors opened with enough force to rebound off the stone walls, producing a thunderous crash that prompted more than one student to fall off their seats, and several more prepared students to immediately reach for their wands, as well as all the professors.

Well.

All the professors except the new Defense Against the Dark Arts professor, who was new this year after Professor Merrythought’s abrupt retirement at the end of the previous year.

The strange old man, Professor Antwork, wore an expression of resigned irritation rather than shock, as he stood far more slowly than his coworkers, drawing his knotted old wand.

“_Grindelwald!_” A voice bellowed, as its owner strode confidently down the center of the hall towards the staff table, entirely ignoring the dozens of wands pointed in his direction, even as more students caught on and joined the number.

Several students and even a few younger staff members flinched at the call, as the dark lord’s name had become something far more commonly whispered about in dark corners than shouted out in public.

In response, however, the DADA professor sighed.

“You’ve just abandoned any precedence of subtlety now, I see,” the man said, and after a startled pause, several wands shifted in the man’s direction as conclusions were drawn.

At the far end of the table, the transfiguration professor turned abruptly several shades paler as his wand stayed pointed at the stranger, still striding towards the table, but his eyes focused on the other professor.

The stranger, who had clearly seen the wrong end of a wand (or several) from his slightly scarred skin and rugged cloak, as well as the danger implied in his confident and battle-ready stance, merely scoffed at this, still carelessly ignoring everyone else in the room.

“I’d say _ subtlety _ has long since been trampled by raging hippogriffs, with the damage you’ve done already, Grindelwald,” he replied, glaring at the man through silver, round glasses.

“_Excuse me_,” was interjected before the professor could reply, and for the first time, the stranger gave any notice at all to the wizened headmaster, who had spoken.

Dippet was one of the many whose wand was still pointed at the stranger, but the man didn’t even point his own, which was drawn but not raised, in the headmaster’s direction.

The younger man simply raised an eyebrow at the interruption.

“Who are you, to barge into a school-- without any detection from the centuries-old wards-- and start shouting such--”

Dippet cut himself off in surprised offense when the stranger rolled his eyes.

“He even _ responded _ when I called him Grindelwald,” the man said, shaking his head slightly, and a loose strand or two fell out of place from his roughly knotted-back hair. “Honestly, _ wizards, _” the man muttered, his non-wand hand over his short beard.

“Yes, they’re quite oblivious, aren’t they,” Grindelwald responded, and a few more wands shifted towards him as he idly walked around the edge of the staff table.

The younger man didn’t move his eyes off him, hawk-like.

“Oblivious enough for you to simply leave them to their own fates,” Grindelwald continued, and though it was phrased as a question, his voice didn’t lilt at the end, clearly expecting a refusal.

“Unfortunately,” the man replied, “I’ve been told I have a bit of a--”

“--_ saving-people thing_,” they finished together.

“Yes, I’ve heard,” Grindelwald continued.

“Don’t even think about it,” the man said, and quicker than most eyes could follow, Albus Dumbledore was suddenly wandless, the stick in question flying past the man as he side-stepped it, letting it clatter onto the ground between the Hufflepuff and Ravenclaw tables rather than try to catch it.

Grindelwald, somewhat surprisingly to the rest of those watching, didn’t take advantage of the momentary distraction.

In fact, the entire thing was still downright unnerving for the students in particular, as the two men were still casually ignoring the number of people around them.

“You really shouldn’t be too hasty to throw your lot in with him,” the man remarked idly, gaze flickering over to the man in question before returning to the disguised dark lord, who was finally letting his appearance shift back.

His shift into a far more recognizable-- although distinctly _ older _ than expected-- figure finally unfroze the Gryffindor and Ravenclaw students closest to him, who all stumbled back out of their seats and away from the pair, quickly followed by the other two houses.

Most students, except a few more sensible Ravenclaws and Hufflepuffs, didn’t entirely leave the hall, however, instead crowding back against the walls and continuing to watch the spectacle.

After a shout or two to clear the hall from the teachers were ignored, shields were finally cast between the students and the pair, even though no one directly engaged the men.

“After all, while back in our dimension, _ you _ were the one who cast that spell, in _ this _ world, you did.” Continuing as if none of this were happening around them, the stranger spoke again, although it was clear no one except Grindelwald and the now-extremely pale Dumbledore understood that comment.

“_Your _ dimension?” Dippet interjected again, eyes widening and flickering between the two.

“Oh yes,” the man said faux-casually after a brief and silent conversation between he and the famed dark lord, which apparently ended with Grindelwald continuing to stand by and allow the explanation. “The resident dark lord over here,” the man waved his free hand at the wizard in question, who gave a slight mocking bow in response, “waited a few years after hearing both his childhood friend over there and the _ newest _ dark lord were dead, then escaped Nurmengard and eventually stole several of the Unspeakables’ newly-created Dimension Turners from the Department of Mysteries. Resulting in my several years-long hunt to chase down him and the others he decided to hand out the Turners to like they were sweets.” The man concluded, having waved his hand in the transfiguration professor’s direction when mentioning him.

There were several moments of ringing silence as that sank in with their audience. Grindelwald seemed distinctly amused by their shock, while the other man seemed more annoyed by his recalled memories.

Everyone else was busy processing the several mind-blowing (and timeline-ruining) revelations in that information dump.

Not the least of which being the implication that Albus Dumbledore, the slightly-batty transfiguration professor and stout Gryffindor was childhood friends with a version (or several) of Gellert Grindelwald, and that once Grindelwald was somehow defeated, there would be at least one more dark lord fairly soon thereafter.

(However, several aspiring Unspeakables did note that in the future, dimension travel would become possible as well, and a few even wondered if the future inventor of that device was currently in the great hall-- or even would be a _ child _ or _ grandchild _ of one of them. More than one brain figuratively gave a puff of smoke and spluttered to a halt at the thought.)

“You really have done a number on this dimension’s timeline already,” the man addressed Grindelwald again, evidently going back to ignoring the rest of the hall. “You’ve been here, what, a year?”

At the dark lord’s nod, he huffed out a breath.

“A single year, and you not only murder your local counterpart and take his place without anyone apparently noticing, _ again _\--”

\--Several more brains spluttered to a halt at that, including one Albus Dumbledore’s yet again.--

“-- but then you actually cross into the British Isles to what, murder the Hogwarts Defense professor and take her place? What is it with you dark lords and your obsessions with that post? Where’s the evil plot in all of that? You got bored with attacking the muggles this dimension around?”

Grindelwald gave a chilling grin, with a manic edge to it that practically shouted “_I’m not entirely sane!_” at the top of its lungs, with an accompaniment of bagpipes just in case the message was missed.

“Oh no, Mr. Potter, I couldn’t care less about the post, unlike that young upstart,” he replied, his eyes flickering briefly towards where most of the Slytherins stood against the walls.

This went largely unnoticed, except by the man he was speaking to and a few of the Slytherins in question. More might have noticed if one of the Gryffindors hadn’t suddenly inhaled sharply enough to start a short coughing fit which distracted several of those around him.

“I have merely started... an experiment, if you will,” Grindelwald continued.

“An _ experiment_?” The claimed-Potter repeated.

“Oh yes,” Grindelwald said, his smile growing. “I simply wanted to see what would happen if interfered in various key points in this timeline. Oh, most of my changes were minor,” the dark lord waved his free hand dismissively, “but then I decided to try changing a few... key events.”

Green eyes narrowed.

A flicker of Grindelwald’s eyes, followed by a sharp inhalation by the dimensionally-displaced Potter were the only warnings the rest of the room had before Grindelwald spun, raising his wand, not towards his opponent or even the teachers, but closer to the hall’s entrance.

“_Avada Kedavra!_” He shouted, and the Slytherins in his chosen direction didn’t have time to move, packed together as they were, before the spell headed towards them, shattering the professors’ still-raised shield as it passed through.

Dark eyes widened as Tom Marvolo Riddle froze.

Only to widen even further when the Potter managed to intercept the spell, falling to the stone floor with empty green eyes staring upwards, still widened in surprise, instead.

The students around him finally panicked, running for the doors, but Tom Riddle remained frozen, staring at the dead man’s eyes, while the professors hurriedly began flinging spells at Grindelwald, who laughed as he blocked or side-stepped their spells, returning fire rather _ literally _ in reply. It was obvious the teachers had never fought together, as half the time they were hindering each other instead of helping, but the much-elder dark lord could take them on with ease regardless.

It was only because he remained frozen, dark brown eyes locked onto green, that Tom noticed when the dead man suddenly _ wasn’t _.

Green eyes blinked, focusing before meeting brown, and the Potter’s face twitched oddly before he winked and slowly stood, careful not to draw the attention of the duelers across the room.

Losing sight of the no-longer-empty eyes finally restarted the young Slytherin’s brain, and he quickly but quietly backed further away, careful to keep objects between himself and the dark lord, which he could dodge behind if another curse were sent his way.

The effort proved unnecessary as, even with the widening of several pairs of eyes as warning, Grindelwald couldn’t disengage from battling the professors in time to block the Potter’s simple stunner from behind.

Ducking the last several stray spells that passed through where Grindelwald had been standing moments ago, the Potter cast a quiet _ Incarcerous_, binding the stunned man, and then an _ accio _ which didn’t seem to produce any results, if the man’s responding frown and the lack of flying objects was any hint.

“Y-You! You were _ dead_!”

Potter glanced up at the professor who shouted.

“Yes, it doesn’t quite tend to stick with me,” he replied.

His mouth twitched slightly at their clear frustration by his non-answer.

“There is no blocking the killing curse, my b--”

Dumbledore’s statement was halted by the tip of a wand suddenly being held under his nose (to the silent glee of one watching Slytherin).

“Call me ‘_my boy_’ or any other patronizing thing like it, and I might just forget that you haven’t done half the things the Dumbledore in my dimension did, and take _ you _ back with me too,” Potter threatened.

It was said with enough venom that the professors nearest Dumbledore edged away from him slightly, not wanting to draw any of the man’s ire on themselves by proximity.

“Now,” Potter stated firmly, “I will not be explaining my life’s story to any of you, as it is _ none of your business_, and I will be taking him,” he lightly nudged Grindelwald’s body with his foot, “finding where he hid his dimension turner, and going back to our dimension. Unfortunately I don’t know everything he’s done to change your timeline, and considering your version of Grindelwald is dead at least a couple years before he should have been defeated, your timeline is irreversibly altered anyway, so you’re just going to have to figure things out on your own. Merlin knows I’m not sticking around to try and _ fix _ it, since the typical pattern wasn’t all that great to begin with. So; I’m leaving. Try to stop me and you’ll just end up stunned too.”

The man ignored the professors’ protests as he levitated Grindelwald’s body, muttering something under his breath about Grindelwald not having been a problem _ much sooner _ if more people simply used stunners, and began walking out of the hall.

He was only a dozen or so steps from the door, and where Tom Riddle was still silently watching (and further along in the entrance hall, a few heads of curious students and portraits peered out from behind corners and doorways and picture frames), when he paused once more to sharply spin on his heel.

He pointed towards Albus Dumbledore with his free hand, stabbing it through the air with clear annoyance.

“Oh, and if any of you get the grand idea of putting _ that manipulative bastard _ in the position of headmaster, just know that yes, not only was he childhood friends with Grindelwald, but they planned domination over the muggles together, _ Dumbledore _ came up with the phrase ‘for the greater good,’ and he will happily stand by as the rivalry between Gryffindor and Slytherin reaches deadly levels. Oh right, and he has no problem endangering students for absolutely no good reason at all.”

And with that parting shot, Potter strode out of the great hall, Grindelwald floating along behind him, and made steady tracks directly out of the castle, a stunned silence in his wake.

It took several long moments before the professors began to rally again, and the headmaster simply looked at his transfiguration professor when the man tried to slip away, halting him in his tracks, as the others began to check over the students.

And one Slytherin in particular, momentarily forgotten, continued to stare in the direction of the entranceway, mind whirling.

Because that wasn’t any manner of ritual or spell that he’d read about, and he thought he’d researched all known methods of gaining immortality.

He’d _ missed _ something.

Dark eyes narrowed.

And the timeline changed.

**Author's Note:**

> I had way too much fun writing this. And at some point it just became a thing for me to purposefully never actually give Harry's first name in this fic, hahahaha...
> 
> And god, this was my first fic in like...two and a half years. I am so sorry.


End file.
